EXECUTIVE SUMMARY

Results of a new study add confirmatory evidence that vaccination with Gardasil 9 can reduce 90% of cervical cancers worldwide.

  • The vaccine is designed to target four types of human papillomavirus (HPV) — 16, 18, 6, and 11 — as well as an additional five HPV types that are the next most commonly associated with cervical cancer (HPV 31, 33, 45, 52, and 58).
  • Researchers from the international study conclude that the 9-valent vaccine potentially could provide broader coverage and prevent 90% of cervical cancer cases worldwide.

Results of a new study add confirmatory evidence that vaccination with Gardasil 9 (Merck and Co., Whitehouse Station, NJ) can reduce 90% of cervical cancers worldwide.1 The vaccine is designed to target four types of human papillomavirus (HPV) 16, 18, 6, and 11 as well as an additional five HPV types that are the next most commonly associated with cervical cancer (HPV 31, 33, 45, 52, and 58). Researchers from the international study conclude that the 9-valent vaccine potentially could provide broader coverage and prevent 90% of cervical cancer cases worldwide.1

“We’re on the verge of a dramatic change
that will positively affect all individuals, particularly women, in the United States,” said lead author Warner Huh, MD, professor and director of the
University of Alabama at Birmingham (UAB) Division of Gynecologic
Oncology and a senior scientist at the UAB Comprehensive
Cancer Center, in a statement accompanying the study. “The challenge is to get the new vaccine into widespread use among young women.”

The Food and Drug Administration (FDA) approved the vaccine in 2014. In October 2016, the FDA approved a two-dose schedule for HPV vaccine for adolescents ages 9-14. (Contraceptive Technology Update reported on the change; see the January 2017 article, “Just Two HPV Shots Recommended for Younger Teens” available at http://bit.ly/2li1dma.) In individuals ages 15-26, Gardasil 9 is administered with a three-dose schedule at 0, two months, and six months.

More Than 100 Sites in Study

More than 100 sites in Austria, Brazil, Canada, Chile, Colombia, Denmark, Germany, Hong Kong, Japan, Mexico, New Zealand, Norway, Peru, South Korea, Sweden, Taiwan, Thailand, and the United States participated in the randomized, double-blind efficacy, immunogenicity, and safety study. Half of the 14,215 women, ages 16-26, received the quadrivalent vaccine, with the other half vaccinated with the 9-valent shot. All participants received gynecological exams for six years to look for evidence of infections or disease, and with blood tests performed to check antibody levels against HPV.

Data indicate the 9-valent shot showed 97.4% efficacy to prevent infections and disease caused by the five additional HPV genotypes not included in the quadrivalent vaccine. The 9-valent shot also produced similar antibody protection against the four HPV genotypes found in the quadrivalent vaccine. Both vaccines had similar safety profiles.1

The 9-valent vaccine now is licensed in more than 40 countries for the prevention of HPV-related anogenital cancers and pre-cancer, and genital warts, says Anna Giuliano, PhD, Director of the Center for Infection Research in Cancer at the Moffitt Cancer Center in Tampa. Guiliano served as one of the investigators in the trial.

“The results of this study support comprehensive vaccination programs and inform public health decision related to implementation,” said Giuliano in a press statement accompanying the study.

Is ‘Herd Immunity’ Taking Effect?

Results from another recently published study indicate that the decline in HPV infections among unvaccinated 18- to 26-year-old women suggests that young women in the United States are beginning to benefit from herd immunity resulting from the introduction of the HPV vaccine.2

To review the changes in vaginal HPV prevalence between 2009-2010 and 2013-2014 among U.S. women who were vaccinated and unvaccinated, the researchers used cross-sectional survey data from three different cycles of the National Health and Nutrition Examination Survey to assess HPV prevalence among women ages 18-59. The information was separated into four age groups (18-26, 27-34, 35-44, and 45-49) to look at the changes over time among the women of different age groups after the vaccine became available. The researchers used multivariable analyses, which controlled for descriptive variables, to assess the prevalence of quadrivalent vaccine-type HPV according to the women’s vaccination status.

The analysis indicated a “significant decrease” in the prevalence of vaccine-type HPV among women ages 18-59 from 2009-2010 to 2013-2014. The decline was only significant in those ages 18-26 when the sample was stratified into the four age groups, researchers note. Among women ages 18-26 who were vaccinated, the HPV prevalence stayed low from 2009-2010 (3.9%) to 2013-2014 (2.0%; prevalence ratio 0.51, 95% confidence interval [CI], 0.18-1.46). Women ages 18-26 who were unvaccinated also showed a decrease over the time period, from 19.5% in 2009-2010 to 9.7% in 2013-2014 (prevalence ratio 0.44, 95% CI, 0.22-0.91). Among the women 26 years of age or older who were unvaccinated, the prevalence did not change greatly.2

Data Adding Up

Clinical evidence has been published recently to support recommendations by the Centers for Disease Control and Prevention (CDC) for a two-dose HPV vaccine to prevent genital warts, showing that the two-dose vaccine provides the same level of protection as three doses.3 (See the August 2017 article, “Researchers Affirm Effectiveness Of Two-Dose HPV Vaccine,” at http://bit.ly/2txoDbW.)

Conducted by researchers from the Boston Medical Center, Boston University School of Medicine; the Veterans Affairs Boston Healthcare System; and the Lombardi Comprehensive Cancer Center at the Georgetown University Medical Center in Washington, DC, the study looked at nearly 400,000 U.S. females ages 9-18 to determine the rate of genital warts based on the number of doses of vaccine that were received. The analysis indicates that receipt of two or three doses of the vaccine was effective. Both regimens provided significantly more protection against genital warts than a single dose or no doses of the vaccine.3

What can you do to increase vaccination rates? According to the CDC, receiving a recommendation for vaccination from a provider is the main reason parents choose to vaccinate their children. Clinicians make use of available opportunities by recommending the HPV vaccine strongly to parents of children 11 to 12 years of age at the same time and in the same way that they do for Tdap and meningococcal vaccines.

Recent data indicate that six of 10 U.S. parents now are choosing to have their teens vaccinated against HPV.4 However, while most teens are receiving their first dose of the vaccine, many are not completing the full vaccination schedule, data indicate. (Get more information; see the November 2017 article, “More Parents Choosing The HPV Shot For Teens,” at http://bit.ly/2fVqL7m.)

The implementation of the Affordable Care Act (ACA) may have aided in vaccine uptake. Results of a recent analysis compared vaccination rates for HPV before and after ACA implementation among females, and examined variation by insurance status and other sociodemographic variables. The proportion of females who reported HPV vaccination increased over time from 16.4% to 27.6%, and those who reported completing the vaccination (receiving three doses) increased from 56.8% to 67.2%.5

After implementation of the ACA, respondents were 3.3 times more likely to be vaccinated compared to before ACA implementation (95% CI = 2.0,5.5), adjusting for age, race, and insurance coverage, data analysis indicates. The respondents were more likely to have received two doses (odds ratio [OR] = 2.8, 95% CI = 1.5,5.3) or three doses (OR = 5.8, 95% CI = 2.5,13.6) of the vaccine. The increase in vaccination could be related to the additional coverage of preventive services, including vaccines, that is required by the ACA, researchers note.5

REFERENCES

  1. Huh WK, Joura EA, Giuliano AR, et al. Final efficacy, immunogenicity, and safety analyses of a nine-valent human papillomavirus vaccine in women aged 16-26 years: A randomised, double-blind trial. Lancet 2017; doi: 10.1016/S0140-6736(17)31821-4.
  2. Berenson AB, Hirth JM, Chang M. Change in human papillomavirus prevalence among U.S. women aged 18-59 years, 2009-2014. Obstet Gynecol 2017;130:693-701.
  3. Perkins RB, Lin M, Wallington SF, Hanchate A. Impact of number of human papillomavirus vaccine doses on genital warts diagnoses among a national cohort of U.S. adolescents. Sex Transm Dis 2017;44:365-370.
  4. Walker TY, Elam-Evans LD, Singleton JA, et al. National, regional, state, and selected local area vaccination coverage among adolescents aged 13-17 years — United States, 2016. MMWR Morb Mortal Wkly Rep 2017;66:874-882.
  5. Corriero R, Gay JL, Robb SW, Stowe EW. HPV uptake pre- and post-Affordable Care Act: Variation by insurance status, race, and education. J Pediatr Adolesc Gynecol 2017; doi: 10.1016/j.jpag.2017.07.002.